(or Einstein–Rosen bridge
or Einstein–Rosen wormhole
) is a speculative structure linking disparate points in spacetime, and is based on a special solution of the Einstein field equations.
A wormhole can be visualized as a tunnel with two ends at separate points in spacetime (i.e., different locations, or different points in time, or both).
Wormholes are consistent with the general theory of relativity by Einstein, but whether wormholes actually exist remains to be seen. Many scientists postulate that wormholes are merely projections of a fourth spatial dimension, analogous to how a two-dimensional (2D) being could experience only part of a three-dimensional (3D) object.
A wormhole could connect extremely long distances such as a billion light years or more, short distances such as a few meters, different universes, or different points in time.@FirstSpaceChat